Today, Verizon put a date on its intention to shut down its aging 3G network: December 31st, 2022. It's not just the end of the extremely widespread 3G system, but a watershed moment for Verizon, since its network began on CDMA technology when the company was first formed in 2000. Greater reliance on the GSM-based LTE network, and finally pushing more customers towards 5G, has let the company wean itself off of the outdated standard.
Verizon originally planned to shut down 3G operations at the end of 2019, but extended it to 2020 and beyond in order to transition as many of its customers off older smartphone and networking hardware. It hasn't allowed the certification or connection of new 3G-only devices since 2016 in preparation. According to industry analyst OpenSignal, Verizon's 4G network covers 97.7% of its total coverage area as of January 2021, so it's possible that a few of the most rural Verizon customers may lose service after the transition.
Verizon says that it's encouraging 3G-only customers to transition now, and that those who don't may experience "degradation or complete loss of service" even before the cutoff date.